If a trumpeter’s sound grows pinched in later years (Miles Davis), scribbling (Don Cherry), or it thins (Freddie Hubbard), Stockhausen’s seems to have reached a glorious peak.

In the girl one sees the woman; in the man, the boy? Meeting Markus Stockhausen in the wings after a duo concert in Germany reminds me of his 1980s performance photos: no longer a boy even then, but boyish, wraithlike, something of Peter Pan in the regard. A web check confirms the pictures are of famous papa Karlheinz’s sui generis late creation Donnerstag, that stunned audiences and left one critic remembering the “brilliance” of trumpeter Markus more than 30 years later. On stage earlier, he produced a trumpet sound of such startling bell-like resonance and beauty that one was left floating, adrift suddenly, wondering whether spirits might live in the trumpet of Markus Stockhausen.

I remembered that young Mozart reportedly passed out when he heard a trumpet played in the open air for the first time. On his new CD Alba with recent Lee Konitz pianist Florian Weber (Stockhausen’s first for Manfred Eicher’s ECM in 15 years) there’s a track – just a fragment really – where he blasts impromptu trumpet notes into the body of Weber’s piano. The effect is mesmerising, transporting, as of a glorious colour field slowly rising.

For a telephone interview three months later, he comes on the line saying he doesn’t want to talk about music in “conventional terms”. The facts-based approach I presume, of influences, discographies, practice routines. But I would like to ask about one of the most significant father-son relationships in modern music. He recalls rocky moments in the 90s, Markus making his way now as a polygenre trumpet-player, neither jazz nor classical but clearly sourcing both – until the break. “In a way our final farewell started in 2001 when I decided not to play his music anymore, and I went through all kinds of feelings – of guilt; of missing him. It was like this long fade, so when he died (in December 2007), it was another step in that feeling of farewell.”

Stockhausen’s improvising ability was plainly evident early – hear his bright-toned Strahlenspur solo on Rainer Brüninghaus’s Continuum (1984) – but it was perhaps only after his father’s passing that true colours really started to come. Out from under, the technique that made jaws drop began to be channelled more effectively. The sound certainly changed, growing fuller, rounder, developing this magnificent, steely resonance.

Prompted, he talks about Freddie Hubbard’s First Light as a major early influence, the visionary Miles of In A Silent Way and Bitches Brew, and Kenny Wheeler for his sheer musicality. Yet at a rigorously cleanliving58, Stockhausen’s tone is probably fuller than Freddie’s ever was and certainly than it became. If a trumpeter’s sound grows pinched in later years (Miles), scribbling (Don Cherry), or it thins (Freddie), Stockhausen’s seems to have reached a glorious peak.

In the decade to 2012, he tells me, he put out 12 CDs of his own music on his Cologne-based Aktivraum label. But there was plenty of other music on other little labels. Taken together, this may be why the recordings are not better known. Still, there’s some very fine improvisation on Joyosa (2004) – his solo on Mona a melodious gem – the exquisite Streams with guitarist Ferenc Snétberger (2007), or Electric Treasures (2008), a live small group recording with pianist Vladyslav Sendecki that is a veritable cracker.

Partly for having lived through the demanding rigours of father Stockhausen Inc. – musicians starving themselves for days before performance and so on – his capacity to blend into musical contexts set by others is remarkable, and rare for a trumpet player (not generally retiring types). Room-transfiguring moments open pianist Antoine Hervé’s Invention Is You (2001), while on Michel Portal’s excellent Dockings (1998), Markus very nearly takes the honours.

Twenty-five years of intense closeness with the dominant post-war composer however, inevitably left their mark, not least by imprinting the primacy of music’s spiritual dimension. “Improvising is one of the most intimate things you can do with another person. It comes very near to love-making,” he says.

Today, about half Stockhausen’s time goes on the duo with Weber, another with clarinettist Tara Bouman, and his highly original Quadrivium quartet. Much of the rest is dedicated to seminars and conferences called “Singing and Silence”, “Healing Sound” and “Intuitive Music” (a term conceived by Stockhausen Snr). Why so? “First because of my own personal quest and this inner need to be in that spiritual sphere. Sometimes it’s even more intense and nearer to me than in certain concerts, which have more of a virtuoso or entertainment aspect.” That intensity can be tested on Alba (released this month) and when Stockhausen and Florian Weber appear at the Royal Northern College of Music in Manchester on Tuesday 31 May.

Picture: Gerhard Richter, www.richterkoeln.de